The measurement of differential pressure is important in many applications such as those measuring oil pressures, fuel pressure, hydraulic pressure, air pressure, and the like. In many of these applications, it may not be desirable to measure differential pressure by applying different pressures to opposite sides of a sensor's diaphragm. Instead, a half-bridge sensor configuration may be used, such as described in U.S. Pat. No. 4,695,817, entitled “ENVIRONMENTALLY PROTECTED PRESSURE TRANSDUCERS EMPLOYING TWO ELECTRICALLY INTERCONNECTED TRANSDUCER ARRAYS,” issued Sep. 22, 1987 to Dr. Anthony D. Kurtz et al, and assigned to Kulite Semiconductor Products, Inc., the assignee herein. This configuration has many benefits but may be susceptible to temperature differences, since each side of the differential sensor may be physically located in different environments. In some applications, a hot liquid such as engine oil may be applied to the front-side of the sensor's diaphragm, while a cool gas such as atmospheric air may be applied to the back-side of the sensor's diaphragm. In this case, compensating for the temperature difference between each side of the sensor's diaphragm may be difficult. Typical temperature compensation of half-bridge sensors assume that both sensors are at the same temperature, so that any temperature effects may be compensated using temperature compensation techniques such as described in U.S. Pat. No. 3,245,252, entitled “TEMPERATURE COMPENSATED SEMICONDUCTOR STRAIN GAGE UNIT” issued Apr. 12, 1966 to Dr. Anthony Kurtz et al., and assigned to Kulite Semiconductor Products, Inc., the assignee herein.
FIG. 1 illustrates a prior art sensor assembly 100. The prior art sensor assembly 100 includes a first transducer 101, a first header 102, a housing 103, a second transducer 104, a second header 105, a shell 106, and a main port 107. In FIG. 1, the first transducer 101 forms a first half of a Wheatstone bridge and the second transducer 104 forms a second half of the Wheatstone bridge. The first transducer 101 is disposed within the first header 102, which is directly connected to the housing 103. Pressure at the main port 107 is applied to a front-side of the first transducer 101. The second transducer 104 is disposed within the second header 105, which is connected to the prior art sensor assembly 100 using the shell 106. The shell 106 may not transfer heat efficiently, so any uneven temperatures applied at the main port 107 of the sensor assembly 100 may cause a large thermal gradient across the body of the sensor assembly 100. The sensor assembly 100 may use the first transducer 101 to measure a first difference between a main pressure at the main port 107 and a third pressure such as atmospheric pressure. The sensor assembly 100 may use the second transducer 104 to measure a second difference between a reference pressure and the third pressure such as atmospheric pressure.